[mythtvnz] New Hard Drive not performing well

[Ross Williamson]

 Hi all

 For what it's worth, I had severe performance difficulties on some 1TB 
 WD Green drives purchased when they first appeared. They did not have 
 warnings of 4K sector size so it is possible that these were the old 
 size.

 I was getting around 1MB/s write speeds which is pretty awful even for 
 a storage drive, especially with streaming data coming in!

 After seeing that it was going to take over a week to sync a RAID1 
 array I thought that there must be some sort of issue here. Many hours 
 of investigation ensued but what eventually solved it for me was to 
 disable native command queuing (NCQ) on the particular ports of the SATA 
 card those drives were on. This can be accomplished in a script on 
 startup with

 echo 1 > /sys/block/sda/device/queue_depth

 (replacing sda with wherever those drives are, obviously)

 I now get ~8MB/s write speed which, while still on the slow side, is 
 now adequate for storage.


 Ross